Flexible insole rib for welting

ABSTRACT

An insole rib comprising a rib and a fabric. The rib has serrations along an upper edge thereof. A material surrounds a portion of the rib such that the upper serrated edge of the rib is exposed.

PRIORITY INFORMATION:

This application claims priority to United States ProvisionalApplication Ser. No. 60/581,951 filed on Jun. 22, 2004, which isincorporated herein by reference in its entirety.

BACKGROUND OF THE INVENTION

The traditional method for manufacturing high quality walking shoesincludes the use of a stitched welt. The method utilizes an insole towhich a rib or wall has been attached by adhesive and positionedapproximately 5/32″ to 7/32″ from the edge of the insole. The upper andthe lining, if a lining is present, is lasted to the insole edge andoften to the rib itself. A welt, which may include leather, PVC, rubber,or other suitable materials, is sewn through the upper and lining to thewall of the rib. The top of the rib and any extra upper/lining materialsare trimmed before sole-attaching by means of a temporary adhesive bondwhich is then stitched.

A variety of insole ribs are available. Basically, each of theseconsists of a fiber core covered with a tape or fabric flanged out ateach side to define the rib. The rib is either upright or angled. Theattachment of the insole rib to the insole is virtually the same for alltypes. Originally, the insole rib was applied only to leather insolesbut today the insole ribs are attached to a variety of insoles.

The insole rib is coated with adhesive, usually a neoprene, allowed todry and then stored on a reel. The insole rib is fed from a reel andattached to the insole by a special rib-laying machine which uses a jetof hot air to heat-activate the adhesive immediately prior to the ribbeing attached by a hammering action. It is essential that the rib beaccurately positioned in relation in the insole edge; normally 7/32″from the edge.

The prefabricated rib is essentially a woven textile comprised of eithercotton, polyester or polyester cotton fibers, coated on one side with anelectrometric adhesive and formed around, slit strips of unsaturatedleather board or TEXON®(registered Trademark of Texon International), alatex rubber saturated paper sheet, a cellulosic paperboard, or othersuitable cellulosic material. In attaching the insole rib to the insole,the rib must make two or three turns including a particularly sharp turnat the toe. The turns result in crimps, bumps or puckers-all of whichare objectionable. Currently the insole ribs offered have pinked or cutedges to minimize the problem caused by these turns. Attaching the ribto the insole board causes a loss of flexibility; further, stitching ofthe welt to the rib and sole-attaching, compounds this inflexibility tothe point of making these shoes generally uncomfortable.

In the past there have been only a few methods to bring back theinherent flexibility of the insole board, all of which contribute toother problems: Use of a thinner, more flexible insole often causestears during stitching and sole attaching; use of a lighter moreflexible rib often results in stitching tears and irregularities; use ofmore flexible, lighter soling materials decreases the longevity of theshoe. Also, an unfilled rib has been used in Asia for the same purpose,but doesn't have the intrinsic strength, especially in the higher walledribs.

SUMMARY OF THE INVENTION

An insole of a shoe including a rib with a filler having serrationsalong at least one side thereof to provide intrinsic flexibility to therib. The filler board may be cellulosic in nature. Additionally the ribincorporates a patented twill fabric such as that disclosed in U.S. Pat.No. 5,195,255 assigned to Worthen Industries, to give further stretch asthe serrated rib rounds the sharp corners of the insole, therebyproviding even more flexibility to the system.

BRIEF DESCRIPTION OF THE FIGURES

Other objects, features and advantages of the present invention willbecome more apparent as the description proceeds with reference to theaccompanying drawings, wherein:

FIG. 1 is a bottom view showing an inner sole and an insole rib;

FIG. 2 is a cross section of twill covered rib before being attached tothe sole; and

FIG. 3 is a cross section of a twill covered rib after trimming.

DESCRIPTION OF THE INVENTION

Referring to FIG. 1, is a ribbed insole 10 comprising an insole 12 andan insole rib 14. The fabric formed around the rib and the rib must lieflat on the contour of the sole. It is adhered to the inside usingconventional techniques.

As shown in FIG. 2, the rib 14 is formed by using a serrated cellulosicfiller board and a twill fabric covering having a back side 16 and afront side 18. The serrations 20 in the rib filler are cut approximately50-99% through the standing portion, which may be 7/32″ or 9/32″,depending upon the footwear manufacturer's preference. The higher rib (9/32″) is typically used for the manufacture of steel toe or safetyshoes. During the manufacturing process, the top of the rib is trimmedoff. This exposes the serrated cellulosic material allowing for flexingof the insole. Once the rib 14 has been trimmed prior to sole-attachingas seen in FIG. 3, the top of the standing rib is trimmed off so thatthe serrations 20 are opened sufficiently to allow the rib 14 and insole12 to flex. Although stitching of the welt and sole-attaching stillcontribute to inflexibility, this rib 14 adds 30-50% more flex than isnormally seen using like components (insole, welt, sole) and standardrib.

The foregoing description has been limited to a specific embodiment ofthe invention. It will be apparent, however, that variations andmodifications can be made to the invention with the attainment of someor all of the advantages of the invention. Therefore, it is the objectof the application to cover all such variations and modifications ascome within the true spirit and scope of the inventions.

1. An insole rib comprising a rib and a fabric, the rib havingserrations along an upper edge thereof; the material surrounding aportion of the rib such that the upper serrated edge of the rib isexposed.
 2. The insole rib of claim 1, wherein the rib filler isserrated approximately 50-99% there through.
 3. The insole rib of claim1, wherein the fabric is twill.